Field of the Invention
The present disclosure relates to a safety system and method to avoid collision between vehicles and other assets in an underground mine based upon computer vision information, asset tracking system information, and motion information.
Description of the Related Art
As background, the following U.S. patents and published patent applications are hereby incorporated by reference herein in their entireties: U.S. Pat. No. 8,527,172; U.S. Pat. No. 8,280,621; US 20070021915, U.S. Pat. No. 6,553,130; U.S. Pat. No. 6,226,389; US 20040022416; and US 20130278440.
Prior art vehicle safety systems for detecting and communicating dangers are commonly comprised of one or more camera sensors, visual monitoring displays, and short range proximity sensors such as ultrasonic or infrared sensors. The camera sensors provide a view of areas not otherwise seen by the driver, and can be visible light sensors, short wave infrared sensors, or long wave infrared sensors, also referred to as thermal cameras. The visual monitoring display is positioned so that the driver can view what the video camera is capturing, and determine whether there is a danger of colliding with an object if the driver proceeds in the current direction. Proximity sensors can be paired with a camera system to detect objects within range and generate audible and visual warnings to the driver. These safety systems, whether limited to only a camera or proximity sensor or encompassing a combination of camera and proximity sensor, provide good localized coverage for detecting objects within a defined proximity, and communicating a level of danger to the driver to avoid collision between objects within a defined line-of-sight distance. Some prior art camera systems add infrared illuminators and sensors to obtain a visible picture of an otherwise visibly dark object. Similarly, some prior art camera systems use thermal imaging to provide a visible picture of naturally emitted infrared energy. Proximity sensors are often paired with these systems to detect and alert of dangers, while a small number of camera systems pair with asset tracking systems to communicate collision dangers of assets rather than generic objects or heat sources. In addition, some of these systems provide automated controls for slowing or stopping or providing audible and/or visual notification to multiple levels of danger.
Prior art tracking systems based on radio signal strength measurements between fixed and mobile objects can also determine positions of equipment and personnel. These systems measure distance between fixed radio transceivers at known locations and mobile radio transceivers using radio frequency (RF) signal strength. For example, a position for the mobile units can be determined using trilateration algorithms based on multiple received signal strength indicators (RSSI). Precision of the calculated location is subject to such factors as the quantity and bearings of the fixed transmitters, interference of the RF signals, and RF signal-to-noise measurements. At best, these systems provide an estimation of the distance to a tracked object and are insufficient as a collision avoidance system on their own.
The prior art systems described above are not reliable for determining, communicating, and providing collision avoidance safety response to predetermined assets and infrared emitting objects in non-line-of-sight conditions such as underground mines and tunnels. None of these systems comprise a collision avoidance system that detects and responds to moving object threats determined from a combination of thermal computer vision information, asset tracking system information, and motion information of individual objects.